Carboxylic Acids, Esters, Ethers, Amides and Amines

Carboxylic Acid  propanoic acid
The -COOH group can only exist at the end of a molecule for the same reasons as those of the aldehydes. The root parent name of the above was propane and the "e" is dropped and "oic acid" is added. If you have two -COOH groups in a molecule you have a "dioic acid". There is a three carboxylic acid molecule known. It is known as citric acid in citrus fruits.

Esters can only be found in the interiors of a molecule. An ester is made by dehydration of a water molecule from between an alcohol and a carboxylic acid. When naming the ester molecule the alcohol portion is named first.
eg.  methyl ethanoate 
Methyl methanoate is made by reacting methyl alcohol or methanol with methanoic acid (old name formic acid). The alcohol label is dropped and the "ic acid" is replaced by "ate". The names are not joined indicating they came from two separate starting molecules.
+     ------------>   H2O

Examples of some of the more common esters are:

ethyl formate C3H6O2 Fruity, rum-like
ethyl acetate C4H8O2 wine, brandy
ethyl propionate C5H10O2 rum-like
ethyl butyrate C6H12O2 buttery, fruity
ethyl valerate (ethyl pentanoate) C7H14O2 apple
ethyl hexanoate C8H16O2 apple, banana, pineapple
ethyl heptanoate C9H18O2 cognac
ethyl octanate C10H20O2 cognac, apricot
ethyl nonanoate C11H22O2 nutty
ethyl decanoate C12H24O2 cognac, nutty
methyl propionate C4H8O2 rum / black current
methyl butyrate C5H10O2 apple, banana
Ethers     -O-     found only in the interior of two longer chains.
eg. CH3CH2-O-CH3    ethyl methyl ether or methoxy ethane 
CH3-O-CH3                 dimethyl ether or methoxy methane 
CH3CH2-O-CH2CH3 diethyl ether or ethoxy ethane 
Please note that there are no ketone groups on either side. If there were then it would be an acid or maybe a ester. Watch out for these complications.
Acid anhydride  Acid anhydrides are made by the dehydration of water from between two carboxylic acids.
eg.       ethanoic anhydride (made from two ethanoic acids)
 methanoic propanoic anhydride 
  +     --H2SO4--->  + H2O
          ethanoic                      ethanoic                                                ethanoic
            acid                             acid                                                     anhydride
Amide          eg  . propamide
Amides are found in many biological compounds. They are a major part of amino acids (proteins) and urea (urine).
Amine -NH2 without an "O" The key to these compounds is to remember that the N atom has three possible bonds. There are three types of amines based upon these bonding patterns. They are named depending upon the carbon to which they are attached.
   1      a primary amine eg. CH3CH2NH2 ethamine or ethyl amine
   2     a secondary amine eg. CH3NHCH3 dimethylamine
  3 a tertiary amine eg.   trimethylamine (the odour that comes from rotting fish).

Go to the Organic Acids and Anhydrides Worksheet
Go to the Organic Esters and Ethers Worksheet
Go to the Organic  Nitrogen Compound Worksheet